Effective uranium extraction from seawater through immobilization of conjugated microporous polymers on collagen fiber membrane

Abstract

Extracting uranium from seawater has become an important method to supplement the nuclear industry. Herein, we introduce a simple route to load conjugated microporous polymers onto collagen fiber membranes, resulting in a novel membrane adsorbent material (CMPA-F/CFM) for uranium capture. Its Langmuir adsorption capacity reaches 304.9 mg·g−1 (at 318 K), with fast adsorption kinetic of 60 min, and excellent adsorption selectivity with Kd = 4.69 × 104 mL·g−1 under the temperature of 298 K, initial concentration of 50 mg·L-1, and pH = 7, thus allowing a satisfactory adsorption performance in a 7-day real ocean experiment with a uranium adsorption capacity of 1.25 mg·g−1. Furthermore, in continuous dynamic adsorption experiments, CMPA-F/CFM could treat up to 19.0 L·g−1 of low-enriched uranium (LEU) solution (1 mg·L-1), with a uranium removal rate of up to 87.5 % (10 L of seawater). This study demonstrates broad potential application of membrane adsorption in extraction of low-enriched uranium.